Chemical property of snow meltwater in a snowy temperate area

We studied the chemical properties of snow meltwater in a snowy temperate area, where air temperature above the freezing point and rainfall are observed even in mid-winter. The amount of bottom-melt beneath the snow cover in the snowy temperate area we studied was below 1mm day-1, which is similar to the amount in a snowy cold area. However, in the case of winter melting, the pH of the meltwater decreased and its electric conductivity increased correspondingly. As the snowmelt progressed, the oxygen-18(.DELTA.18O) of the snow cover increased gradually, and as a result, the .DELTA.18O of the meltwater also increased accordingly. We conducted a multiple regression analysis with four species of acidifying ions(NO-3 and nss-SO2-4) and neutralizing ions(NH+4 and nss-Ca2+) in meltwater as independent variables and H+ as a dependent variable. We could explain 86% of the H+ concentration fluctuation in meltwater based on the concentrations of these four ion species. A clear diurnal variation is observed in anion concentrations in meltwater at the peak melt season. The anion enrichment factors in meltwater are higher in the order of NO-3, nss-SO2-4 and Cl-, with values of 7.7, 7.2 and 4.0, respectively